100 Journal of Chemical and Engineering Data, Vol. 23, No. 2, 1978
an ice-salt mixture. After 128 g (4.00 mol) of absolute methanol had been added dropwise through the dropping funnel, the reaction mixture was allowed to stir overnight to ensure evaporation of all the excess phosgene. The crude methyl chloroformate was washed with two 50-mL portions of ice water and dried over anhydrous sodium sulfate and calcium carbonate for 1 day. Distillation at atmospheric pressure yielded 280 g (75%) of methyl chloroformate, bp 70-72 OC (reported (2) bp 71.5 OC). A 2-L, three-necked flask fitted with a water condenser, a dropping funnel, and a stirrer was charged with 120 g (0.76 mol) of bis(4-hydroxy-2-butenyl) ether (11), 400 mL of dry chloroform, and 200 g (2.5 mol) of dry pyridine. To the reaction flask cooled at 0 OC was added 235 g (2.5 mol) of freshly distilled methyl chloroformate over a period of 8 h. The reaction mixture was washed successively with 200 mL of water, 100 mL of 5 % hydrochloric acid, and 100 mL of a saturated sodium bicarbonate solution. After the chloroform solution was dried over anhydrous magnesium sulfate overnight, the chloroform was removed by distillation under reduced pressure, and the residue was fractionally distilled through a 12-in., helix-packed column to yield 175 g (84 % ) of bis(4-hydroxy-2-butenyl) ether bis(methy1 carbonate) (IV), bp 155-157 OC (0.8 mm), n30D1.4564. Anal.
Calcd for Cl2HIB0,: C, 52.55; H, 6.56. Found: C, 52.74; H, 6.73. An infrared spectrum analysis of bis(4-hydroxy-2-butenyl) ether bis(methy1 carbonate) (IV) showed strong absorption bands at 958, 1100, 1275, 1450, 1760, and 3000 cm-' indicative of the presence of an aliphatic ether, a covalent carbonate, and a double bond.
Acknowledgment The authors are grateful to Mrs. Kathryn Baylouny and Miss Jane R. Swann for the microanalyses and to Mrs. Baylouny and Dr. Charles E. White for the infrared spectra.
Llterature Cited (1) Arino, P., Camps, F., Serratosa, F., An. Quirn., 66, 303 (1970); Chern. Abstr., 73,87362~(1970);Spanish Patent 386539 (Mar 16, 1973); chem. Abstr., 80, 120254/(1974). (2) Cox, H. E.,Anelyst(London), 64, 807 (1939). (3). General Aniline and Film Corp., "Technical Information", Data Sheet No. A-109 (1945). (4) Pratt, E. F., Draper, I. D., J. Am. Chem. SOC.,71, 2846 (1949).
Received for review August 5, 1976. Resubmitted June 23, 1977. Accepted November 7, 1977. This work was support in part from a grant from the Office of Naval Research and the National Science Foundation.
Synthesis and Fluorescence Spectra of 1,4-Bis( phenylethyny1)anthracene Ronald A. Henry, Dan E. Bliss, and Carl A. Heller" Chemistry Division, Code 385, Na Val Weapons Center, China Lake, California 93555
The synthesis of the title compound, 1,4-BPEA, was accompllshed In the same manner as for 9,10-BPEA, but with lower yield due to a side reaction. The compound Is a fair fluorescer with 60% quantum yleld in benzene. The emission peaks are at 449 and 478 nm In benzene-blue-shifted from 9,lO-BPEA-but stlll red-shifted from 9,lO-diphenylanthracene. Ethanol solutlons peak at 443 and 472 nm with the same quantum yleld. Introduction In a recent paper ( 3 )we gave the fluorescence spectra of several substituted 9,10-bis(phenylethynyl)anthracenes. We have now synthesized a related fluorescer, 1,4-BPEA, measured the fluorescence and quantum yield, and noted how these are affected by this change in the position of the phenylethynyl groups.
Syntheses of 1,4-Bls(phenylethynyI)anthracene and 2-Phenylethynyl-I ,4-dlhydroxyanthracene 1,4-Anthraquinone (6.3 g, 0.0303 mol; mp 221-224 OC, reported (2)) was reacted with lithiophenylacetylide (6.8 g of phenylacetylene, 1.5 g of lithium amide, 85 mL of dry dioxane) in the same manner ( 1) used with 9,lO-anthraquinone. The dark tarry product obtained when the reaction mixture was quenched with 4 g of ammonium chloride in 100 mL of water was separated from the liquid phase by decanting the latter. The crude product was triturated several times with pentane to remove This article not subject to US. Copyright.
excess phenylacetylene and then with water; after drying, the crude product was boiled with 100 mL of benzene and chilled overnight at 5 OC, and the solid (1.8 g) was removed and saved (A). When the benzene solution was diluted with 75 mL of nhexane and further cooled, 3.6 g of olive green solid separated. The latter was filtered and redissolved in 25 mL of acetone and the solution chilled at -15 OC for 3 days, 0.14 g of solid (mp >320 OC; same IR spectrum as that for the following by-product) was removed. This acetone solution was diluted with 20 mL of acetone and added dropwise with stirring to 5.5 g of stannous chloride in 50 mL of 50% aqueous acetic acid. After overnight stirring at 25 OC, the mixture was diluted with 100 mL of water, slurried with some Celite, and centrifuged. The supernatant was discarded. The cake was resuspended in water and centrifuged, and the washings were discarded; this process was repeated twice more. After drying the cake, it was extracted with one 50-mL and two 25-mL portions of boiling benzene. The combined extracts were diluted with 250 mL of cyclohexane and 100 mL of n-hexane and chilled at -15 OC for several days; the supernatant was decanted from the dark resinous material, which had separated, and evaporated to leave 0.8 g of dark yellow 1,4-bis(phenylethynyI)anthracene.Sublimation at pump limit and a pot temperature of 160-170 OC gave felted yellow needles of 1,4-BPEA, mp 164-165 OC. Carbonyl absorptions were absent in the I R spectrum. By fractionally crystallizing the solid A from benzene there was isolated a small amount of greenish yellow solid, mp >320 OC,whose infrared spectrum showed a CO absorption at 1680 cm-'. Although this evidence might suggest a 1+anthraquinone derivative, the 'H NMR spectrum is more consistent with the assumption that this material is the keto tautomer of 2-
Published 1978 by the American Chemical Society
Journal of Chemical and Engineering Data, Vol. 23, No. 2, 7978 181
Table 11. Absorption and Emission Spectra of 1,4-BPEA in Benzene
Table I. Absorption and Emission Spectra of 1,4-BPEA in Ethanol Absor ban cea h, nm
280 282 286 290 296 300 310 321 330 340 350 360 370 3 80 390 400 408 410 420 431 440 45 0 460
Fluorescence emissionb
A , re1 73.4 69.5 74.8 64.4 58.0 61.9 79.9 90.2 51.5 30.9 30.1 35.2 36.6 50.4 63.4 85.6 100.0 99.2 78.9 97.6 58.5 7.3 1.6
h, nm
410 420 430 440 443 45 0 457 460 4 72 480 490 500 502 51 0 520 530 540 550 560 570 5 80 590 600 610 620
&(A),
Absorbancea
re1
0.0 2.2 21.7 89.1 100.0 69.6 47.8 50.0 80.4 58.7 34.8 32.6 32.6 26.1 17.4 12.0 9.8 7.6 5.4 3.3 2.2 1.7 1.1 0.4 0.0
lo4 Slits, 10 nm; excitation at
Fluorescence emissionb
A, nm
A , re1
h, nm
Fq(h), re1
290 300 310 320 323 330 340 350 360 370 380 390 400 411 420 425 430 434 440 450 460 470 4 80
93.1 79 93 110 112 93 47 37 32 34 44 60 73 100 88 84 92 98 89 30 5 1.5 0.0
410 420 430 440 449 460 465 470 4 78 480 49 0 500
0.0 1.2 8.3 55 100 50 48 60.7 76 74 43 29.8 30.0 29.8 21 14 11 8 6 5 4 2.4 1.9 1.2 0.5 0.0
508 510 520 530 540 550 560 570 580 590 600 610 6 20 630
a Slits, 10 nm; molecular absorbances 4408) 1.64 X
M-l, ~ ( 4 3 1 )1.60 408 nm, 0.412 pM. cm-l
X
lo4.
phenylethynyl-1,4dihydroxyanthracenewhich would result from the 1,+addition of lithiophenylacetylideto the starting anthraquinone. 'H NMR (MepSO-d6,100 MHz), 6 5.21 (s, 2 H, CH2), 7.12 (s, 5 H), (C6H5),7.71 (quartet, 2 H, He, H,), 8.15 (quartet, 2 H, Hg, Ha), 8.48 (s, 2 H, Hg, Hie). The sample for analysis was recrystallized from dimethyl sulfoxide. Elemental analyses (C, H, 0) were performed for the 1,CBEA and for this compound and were submitted for review.
Slits, 10 nm; molecular absorbances ~ ( 4 1 1 2.06 ) X l o 4 cm-l Slits, 10 nm; M-', e(434) 2.01 X lo4, ~ ( 3 2 3 2.31 ) X lo4. excitation at 411 nm,0.37 pM. Table 111. Excitation Peaks of 1,4-BPEA Ethanola
a
Benzeneb
A, nm
I , re1
A,nm
I , re1
323 411 432
92.1 98.2 100.0
323 413 435
87.5 96.7 100.0
Slits, 10 nm; 0.412 pM. 12'
Slits, 10 nm; 0.37 pM.
323
110 411
434 1449 478
CY
508
Fluorescence Procedure and Results C CO
The small amount (2.3 mg) of sublimed 1,CBPEA was all used in 25 mL of ethanol to obtain the spectra and quantum yield. Then the ethanol was evaporated and the same material (estimated from ethanol solution proportions as 2.0 mg) was dissolved in 25 mL of benzene. Tables I and I1 give the absorption and emission spectra of 1,CBPEA in ethanol and benzene. The molecular absorbances are given at the peaks. The accuracy of these molecular absorbancies is limited by the accuracy of weighing the small samples and the estimation of the amount of 1,4-BPEA left from the ethanol evaporation. Figure 1 summarizes these data graphically. Table I11 gives the excitation peaks which are close to the absorption peaks. Excitation spectra are quite noisy on this instrument and this accounts for the differences in the peak wavelengths. However, the peak heights of excitation show too large a variation from the corresponding absorption peak heights. The reason is an impurity which showed up as an emission band when we excited the benzene solution at the 323-nm peak. This impurity fluorescence bank peaked around 376 nm. The 1,4-BPEA emission was also present and undistorted. Evidently the excitation/absorption peak differences were due to the impurity absorption around 320 nm and did not affect the work
SOLVENT
30 20
-
1 \
10
I , , , , I , 0 3W
350
I
,
,
1 400
,,Au,
I ,
450
10
0
c
'. '
350
400
450
500
550
nm
! I I ~ ~ ' ' , " , , ~ " - / , ' '
0 300
550
500
WAVELENGTH
20
BENZENE
EMISSION
40
'
1
"
,
1
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500
'
, 1
'
550
500
550
WAVELENGTH, nm
Flgure 1. Absorption and emission spectra of 1,4-BPEA: (top) in benzene, (bottom) in ethanol.
182 Journal of Chemical and Engineering Data, Vol. 23, No. 2, 1978
dark were stable for 3 days in terms of spectra and quantum yields.
Table IV. Ouantum Yields Ethanol Solution Excitation wavelength
Run no.
408 nm
A
0.675 0.65 1 0.661 4 = 0.66 i- 0.07
B C ~
~
431 nm 0.627 0.63
~~
Benzene Solution Excitation wavelength
Run no.
411 nm
A B
0.641 0.629 0.657 0.714 0.677 q = 0.66 ?: 0.03
B C C
434 nm
Discussion In our earlier paper (3) we discussed the problem of corrected spectra and errors in quantum yield. With 1,4-BPEA its spectra are in the same region as the comparison compound (quinine sulfate at 457 nm) so this error is minimized. The emission spectrum structure of 1,CBPEA is much like that of 9, lo-diphenylanthracene (DPA), but the peaks are strongly blue shifted from those of 9,lO-BPEA. The absorption spectrum of 1,4-BPEA is different from both the other compounds. The quantum yield, 60%, is lower than that of the 9,lO-BPEA (81 %)
(3). Literature Cited 0.633 0.63
above 400 nm where we measured quantum yields. We therefore did not pursue the impurity further. The quantum yields in both solvents are given in Table IV. These are in air-saturated solutions. Solutions in air but in the
(1) Donner, W. W.. Reid, Schlegemilch, W., Chem. Ber., 94,1051 (1961). (2) Grinev, A. N., Rotopopov, I. S., Cherkasova, A. A,, J. org.Chem., USSR, 8, 220 (1972);Chem. Abstr., 77, 101277r (1972). (3) Heller, C.A., Henly, R. A., Mckughlin, B. A,, Bliss, D. E., J. Chem. Eng. Data. 19,214 (1974). Received for review August 1, 1977. Accepted January 3, 1978.
Synthesis of Naphthaceno[ 5,6-cd]-I ,2-dithiole Paul J. Nigrey’ and Anthony F. Garito Department of Physics and Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19 104
A single-step synthesis of the a-electron donor naphthaceno[5,6-cd]-1,2-dithioie is reported as well as polarographic data and its formation of a semiconducting salt with tetracyanoqulnodimethane. Considerable interest in the synthesis of planar, aromatic compounds containing exocyclic sulfur or selenium ( 2 , 6, 8) as potential a donors has prompted our investigation of the reaction of sulfur with tetracene in refluxing dimethylformamide (DMF) to form naphthaceno[5,6-cd]-1,2-dithiole (DTT, 2). S-9
product. Goodings ( 1) later was able to isolate 2 in 4% yields from the gradient sublimation of crude 3. We wish to report here a convenient, single stage, preparative route for the synthesis of 2. Gradient sublimed (5)tetracene reacts with 0.25 equiv of sulfur when refluxed for 24 h in anhydrous DMF to give after muRiple gradient sublimation, in a 30% yield, 2,mp 212.7-214.6 OC as violet needles. Attempts to prepare 2 using more than 0.25 equiv of sulfur resulted in the appearance of traces of 3 in the gradient sublimate while using less than 0.25 equiv gave 2 in poor yields (
